小寒大寒，究竟哪个更冷？

Core Viewpoint - The article discusses the differences between the solar terms "Xiao Han" (Minor Cold) and "Da Han" (Major Cold), highlighting that despite their names, the actual temperature data often shows that Xiao Han is colder than Da Han in many regions of China [1][2]. Group 1: Temperature Comparison - Xiao Han marks the beginning of severe cold, while Da Han represents the accumulation of cold [1]. - Meteorological data indicates that during Xiao Han, average temperatures in Beijing range from -5 to -10 degrees Celsius, while Da Han is typically 1 to 2 degrees warmer [2]. - In the Yellow River basin, extreme low temperatures during Xiao Han can drop below -10 degrees Celsius [2]. Group 2: Climate Dynamics - The colder temperatures during Xiao Han are attributed to the strong cold air masses and the "lag effect" of ground heat loss [2]. - After the winter solstice, the ground continues to lose heat, leading to the lowest temperatures being recorded during Xiao Han [2]. - By Da Han, although cold air activity remains, the average temperature slightly increases due to longer daylight and increased solar radiation [2]. Group 3: Regional Variations - In northern China, the cold is characterized as "dry cold," with temperatures often dropping to -20 or -30 degrees Celsius [3]. - In southern China, the cold is described as "wet cold," with temperatures typically between 0 and 10 degrees Celsius during Xiao Han, but more frequent cold air activity during Da Han can lead to lower temperatures [3]. - The perception of cold varies regionally, with southern areas experiencing more discomfort due to humidity and precipitation during Da Han [3]. Group 4: Cultural Significance - Xiao Han symbolizes a period of hidden strength, while Da Han signifies a turning point towards the arrival of spring [3]. - Both terms reflect ancient Chinese sensitivity to seasonal changes and respect for nature [3].